Spiny Waterflea

The spiny waterflea is a small crustacean (zooplankton) with a short body (0.04-0.1 inches) and a long tail (up to 3/5 inch). The tail contains one to three sets of barbs and ends in a long spine.

Preferred Habitat

It can typically be found in open water in lakes.

Reason for ANS Designation

This zooplankton can outcompete other zooplankton for food and change the types of zooplankton available for fish prey. Spiny waterfleas can also foul fishing line and lures due to their long, spiny tails. Once established, there is no good control method.

Place of origin

The fishhook waterflea is native to Eurasia but was introduced to the United States in the 1980s. The initial introduction was likely through ballast water releases into the Great Lakes and subsequent introductions were likely through the movement of water.

Stopping the Spread

When taking equipment out of a lake or stream, remove all plants and mud and drain all water prior to leaving. Allow the equipment to dry completely, rinse with 140°F water for 10 seconds of contact, or disinfect using an approved method such as a .02% bleach solution for 10 minutes of contact time or freezing for 72 hours.